Along with these new screens, they have also released new information, saying:
"With this official add-on for The Elder Scrolls V: Skyrim, journey off the coast of Morrowind, to the island of Solstheim. Encounter new towns, dungeons, and quests, as you traverse the ash wastes and glacial valleys of this new land. Become more powerful with shouts that bend the will of your enemies and even tame dragons. Your fate, and the fate of Solthseim, hangs in the balance as you face off against your deadliest adversary - the first Dragonborn.
Explore Beyond Skyrim - Leave the province of Skyrim and travel to the coastal island of Solstheim. Encounter the Dark Elven settlers of Raven Rock and the native Skaal, as you unravel the mystery of a Dragonborn's return.
Become the Ultimate Dragonborn - Harness the power of the Voice as you face off against the first Dragonborn. Wield new shouts and spells including Dragon Aspect - allowing you to summon the inner power of a dragon to deliver colossal blows and strengthen other shouts.
New Powers - Discover dark powers as you journey into a new Daedric realm. Collect books of forbidden knowledge and choose new paths for your skills and abilities.
New dungeons, creatures, weapons, and more - Suit up in Bonemold and Chitin armors and weild Stalhrim weapons as you navigate through a myriad of dungeons. Battle formidable foes like Ash Spawn, Rieklings and more."
Here's the Dragonborn trailer for those of you that missed it: